Method and apparatus for testing paper currency and the like



May 19, 1964 w. A. PATZER 3,133,641

METHOD AND APPARATUS FOR TESTING PAPER CURRENCY AND THE LIKE OriginalFiled Oct. 24. 1958 5 Sheets-Sheet 1 INVENT OR.

MZZz'am fl. Pager e 14 M422 YW ailorn c js May 19, 1964 w, PATZER3,133,641

METHOD AND APPARATUS FOR TESTING PAPER CURRENCY AND THE LIKE OriginalFiled Oct. 24, 1958 5 Sheets-Sheet 2 INVENTOR. William Page! aziorne 1/5y 19, 1 w. A. PAT ZER 3,133,641

METHOD AND APPARATUS FOR TESTING PAPER CURRENCY AND LIKE Original FiledOct. 24; 1958 5 Sheets Sheet 5 H t M i so I I I l I I I m. INVENTOR.

William A. Page) B 90m, YM

aizorneys W. A. PATZER May 19, 1964 METHOD AND APPARATUS FOR TESTINGPAPER CURRENCY AND THE LIKE Original Filed Oct. 24, 1958 INVENTOR.William A. Pager BY 5 Sheets-Sheet 4 FIG,

flz iarnez s W. A. PATZER May 19, 1964 METHOD AND APPARATUS FOR TESTINGPAPER CURRENCY AND THE LIKE Original Filed Oct. 24, 1958 5 Sheets-Sheet5 United States Patent ()filice 3,133,641 Patented May 19, 19643,133,641 METHUB AND APPARATU FGR TESTENG PAPER CNCY AND THE LIKEWilliam A. Patzer, Chicago, lill., assignor, by mesne assignments, toAutomatic Canteen Company of America, Chicago, Ill, a corporation ofDelaware Continuation of application Ser. No. 769,463, Oct. 24, 1958.This application Oct. 16), 196i), Ser. N 63,235 4 Qiaims. (Cl. wi-4.11.5)

This invention relates to a testing device for the selection and/ orrejection or" imprinted material or other material having configurationsprinted or otherwise incorporated in or on the material and throughwhich light is capable of transmission in an amount depending upon thecharacter of the configurations or imprint and in an amount dependingupon the characteristics of the material itself.

This is a continuation of application Ser. No. 769,403, filed October24, 1958, entitled Test Device and Means (now abandoned), which was acontinuation-in-part of applications Ser. No. 676,527 (now abandoned),and Ser. No. 744,966, now US. Patent No. 3,108,693, issued on October29, 1963.

In general, this invention is addressed to a device by which imprintedmaterial can be separated one from the other in accordance with theimprint or configurations thereon and wherein selected materials can beaccepted while others are rejected, as in the selection of currency ofone denomination as distinguished from another or in the selection oflegitimate currency with the rejection of counterieits. A device of thetype described can be used for various purposes such as in the selectionor separation of checks, stubs, tickets, money and the like.

It is an object of this invention to provide a new and simple means fortesting by light transmission to eifect the selection or separation ofimprinted materials wherein the material itself is capable of someamount of light transmission.

It is a further object to produce a testing device of the type describedwhich is simple in construction, easy in operation, and which iseffective to effect separations based not only upon the amount of lighttransmission through the imprinted portions of the material but which iseffective also to enable testing and/or separation in response to theamount of light transmission through unprinted portions of the material.

These and other objects and advantages of this invention willhereinafter appear and for purposes of illustration, but not oflimitation, an embodiment of the invention is shown in the accompanyingdrawings in which-- FIG. 1 is a front elevational View of the deviceembodying the features of this invention;

FIG. 2 is a top plan view of the test portion of the device shoWn inFIG. 1 with parts broken away for better 'llustration of the interiorportions thereof;

FIG. 3 is a sectional elevational view along the line 33 of FIG. 2;

FIG. 4 is a sectional elevational view taken along the line 44 of FIG.2;

FIG. 5 is a sectional view taken across the line 55 of FIG. 2;

FIG. 6 is a plan view from the bottom side of the device shown in FIG.1, and

FIG. 7 is an electrical diagram of the device shown in the previousfigures.

The description of the invention will be made with reference to the useof the device for testing of currency to provide for the acceptance ofpaper currency of a desired denomination and the rejection of all otherpapers intro duced for test into the machine. It will be understood thatthe reference to currency will be only as representative of the variousimprinted, light transmissible paper or sheet stock which may beprocessed through the machine to effect separation in accordance withvarious configurations embodied therein or thereon or to effectacceptance of certain material and the rejection of others, aspreviously described.

Having briefly outlined the scope of the invention, reference will nowbe made to its construction and operation. The test section,constituting the principal features of this invention, relies upon thetransmission of light through the paper or currency in determination ofthe character of the material and the arrangement or imprint ofconfigurations embodied therein or imprinted thereon. By the directionof rays from a source onto one side of the paper or currency and by thearrangement of suitable responsive cells adjacent the opposite side ofthe currency, use can be made of the cells to measure the amount of raystransmitted through various selected sections of the currency and meansare employed in combination with the cells to control certain operationsas a result of their energization or lack of energization. Byarrangement of the responsive cells so that predetermined cells underlieportions of the currency known to have low light transmission, it ispossible to effect selection and separation of such papers or currency.A pattern can be established which can be met only by currency of apredetermined denomination as distinguished from other currency orpaper. Similarly, a pattern can be established for use with papershaving certain groups of letters or figures, such as checks, tickets,stubs, paper, plastic or the like, as long as the base material has somedegree of light transmission.

As described in the aforementioned copending applications, the paper orcurrency 20 to be tested is positioned within an opening 22 extendingcrosswise of a slide or drawer 2.4 and which is dimensioned to receivethe currency in a fiatwise position. The slide plate 24 is guided by theside bars 26 and 28 for endwise displacement of a flat top 30 on a tablefor movement between a normal retracted position, illustrated by solidlines in FIG. 2, and an operative or test position indicated by thebroken lines in FIG. 2.

When in test position, the paper or currency is interposed between alight source 32 and a plurality of light responsive cells 34 positionedto underlie selected portions of the paper or currency, some of whichare unprinted portions having low light transmission, wherein the cellsare referred to as 34 for the cells underlying the portions printed withgreen and 34 for the cells underlying the portions printed with blackink. The cells underlying the unprinted portions having high lighttransmission are hereinafter referred to as 34. Each of the cell groups,34 34 and 34, has operatively associated therewith an individual meterrelay labelled G, B, and W, respectively. These meter relays areconventional and may be of the type described in the previously citedpatent.

In order for the light to strike the portions of the paper or currencyoverlying the light responsive cells 34, the door 36 which is rockedinto and out of the currency receiving opening 22 is formed with windows38 which are aligned endwise with the cells.

The slide plate 24 is latched in testing position, for the duration ofthe light test and while the acceptable currency is removed, by means ofa latching finger 40 on the end of a bell crank 42 which is adapted torock about its pivot 44 between blocking and unblocking position. Whenin blocking position, shown in broken lines in FIG. 2, the finger 40 isprojected into the path of a block 46 rigid with the underside of theslide plate 24 to prevent return of the slide plate to normal position.When in unblocking position, shown by the solid lines in FIG. 2, thelatching finger is out of the path of the block 46 to enable automaticreturn movements of the slide plate to starting position responsive tothe actuation of spring members 48. Said spring members have one end 50anchored to the table while the other end is anchored at 52 onto a pin54 rigid with the wall 56 constituting a part of the framework fixed tothe top of the table and extending about the test section. Bumpers 58rigid with the table extend into the path of the slide plate to stop thelatter in normal position While other bumpers 60, also rigid with thetable, extend into the path of the slide plate to engage the slide platewhen displaced to test position.

The slide plate and the door are provided with slots 62 and 64respectively which extend lengthwise across the central portion of theopening in alignment with about the center of the paper or currency 20placed in test position therein. The table top is also provided with asimilar slot 66 in alignment with the slots 62 and 64 when the slideplate is displaced to test position to enable the paper or currency tobe displaced from the slide plate as by means of a device, hereinafterreferred to as a currency stripper, or by other suitable displacementmeans.

The currency stripper, in the illustrated modification, comprises avertically disposed frame plate 70 fixed to the frame and adaptedslidably to mount a currency stripper plate 72 for endwise displacementbetween raised or retracted position, as shown in FIG. 4, and lowered oroperated position, as shown in FIG. 3. When in raised position, thelower edge of the currency stripper plate is spaced from the slide plateand, when in operated position, the currency stripper plate extendsthrough the slide plate and the aligned slots to bring the lower edgebeyond the underside of the table. The currency stripper is displacedtoward operated position by a solenoid 74 which operates through rod 76and spring 78 to urge rocking movement of the lever arm 80 about itspivot 82 to effect downward displacement of the stripper with sufficientforce to overcome the restrained force of the coil spring 84. When thesolenoid is inactivated to extend the rod 76, the restraining spring 84becomes dominant to effect return movement of the stripper to normalposition. The stripper plate is guided in its linear movement as bymeans of vertically spaced apart studs 86 and 88 rigid with the frameplate 70 and which extend through an elongate continuous slot 90 in thestripper. The studs further operate to define the movements of thestripper plate between operated and retracted positions of adjustment.

The device is provided with a means on the underside of the table totake over from the stripper plate and complete displacement or removalof the acceptable paper or currency. As illustrated in FIGS. 3 and 6,such auxiliary displacement or removal means comprises a pair of shafts92 and 94 provided with spaced rollers 96 and 98 in operative engagementone with the other in the spaced pairs. One of the shafts 94 isoperatively connected to an aligned drive shaft 100 of electrical motor102 while the other shaft is mounted for free rotational movement inbushings 104 slidably received within slotted openings in the side walls106 depending from the table to enable movement of the one shaft 92 inthe direction toward and away from the other. The shaft 92 isresiliently urged in the direction towards the other shaft 94 by meansof coil springs 108.

The rollers 96 and 98 are spaced one from the other in each pair by adistance which is greater than the width of the stripper plate 72 butless than the width of the paper or currency 20 so that the rollers willengage the paper or currency displaced into the nip by the stripperplate without operatively engaging the plate. Thus the rollers caneffect continued movement of the paper or currency while leaving thestripper plate free to move independently of the paper or currency. Thedrawings in FIGS. 3, 4 and 6 show one test for insuring that the paperor currency has been delivered from the slide plate by the stripperplate. This test comprises a switch arm 110 connected to the switchmember 112 and extending into the path of the movement of the paper orcurrency upon delivery from the drawer by the stripper plate androllers. The switch arm 110 is displaced by the paper or currency tomake the switch 112 as the rollers take over to effect further deliverymovements. The switch 112 must be made before subsequent operations canbe effected, as illustrated by the delivery of proper change for thecurrency of the selected denomination as by means of the mechanismillustrated by the letter C in FIG. 7 of the drawings.

One other test not previously described insures the presence of a paperor currency of the proper dimension before the light transmission testis carried out or before the slide plate is locked in test position.This test comprises two or more switch members 114 and 116 fixed to theunderside of the table in laterally spaced apart relation with switcharms 118 extending upwardly through openings 120 in the table to beengaged by the leading edge of the paper or currency 20 as it isdisplaced into its final position for testing. The switch arms 118 arespaced to be engaged by laterally spaced apart portions of the leadingedge of the paper or currency and preferably to include at least theouter edge portions on each side of the paper or currency. If theswitches are made and remain made during the test operations, thesubsequent locking step and test can be carried out. If the switches 114and 116 are not made, the slide plate does not become latched in testposition and the springs 48 are effective immediately to return theslide plate with the paper still in the opening.

Having described the structural elements, description will now be madein greater detail of the operation of the device as employed incombination with a unit for giving change for a dollar bill. Obviouslyother devices can be operated, if desired, in response to the acceptanceof the currency from the test unit.

In the following description of the operation of the machine, it will beassumed that the coin tubes are properly filled with coins so that theswitch will be made so that no current will travel through the line 132to the empty lamp 134 for indicating when one or more of the tubes areempty. Starting with the slide plate 24 in retracted position, as shownby solid lines in FIG. 2, the door 36 can be rocked about its pivot toraised position, as shown by the broken lines in FIG. 4. This permitsaccess to the opening adapted to receive the paper or currency 20. Afterinsertion of the dollar bill, the door is rocked about its pivot tolowered position into the opening to hold down the dollar bill in thepocket of the slide plate.

The slide plate can be displaced forwardly as by means of the knob 136to test position with the dollar bill properly located between the lightsource 32 and the light cells 34. If the paper placed in the opening ofthe slide plate has a dimension corresponding to a legitimate dollarbill and if it is laid flatwise in the pocket, the leading edge 122 ofthe dollar bill will engage the switch arms 118 of the switches 114 and116 to make the switches during final movement of the dollar bill totest position. This will enable current to flow through line 140 throughthe switch 130 into line 142 and through the switch 144 to line 146.From line 146 the curent flows through the switch contacts ofanti-jackpot relay 148 into line 150 and through the reset relay switch152 into line 154 and through the made switches 116 and 114 into theline 156 to the lock solenoid 158 which is operative to rock thelatching lever 42 to latching position while simultaneously actuatingthe switch arm 1-60 to make the switch 162. This places the latchingfinger 40 into position to confront the block 46 to hold the slide platein test position.

Responsive to the displacement of the latching lever to latchingposition, the switch 162 is made, as described, to enable current toflow from the outlet in line 164 to line 166 to the starting relay 168.The starting relay makes the switch 170 to enable current to flowthrough line 172 to the timing motor 174. The timing motor actuates arotor 176 having one contact in engagement with the center strip 178connected to the inlet through line 180 while the other contactsequentially engages a light strip 182, a switch relay strip 184, astripper strip 186, a reset strip 188, and a motor strip 190 beforereturn to starting position.

It will be apparent that if less than all of the switch fingers 118 areengaged to make the switches 114 and 116, current will be incapable offlow as described to the lock solenoid 158. As a result, the latchinglever 42 will not be rocked to latching position so that the slide platewill be free for immediate return by the springs 4-8 with the paperstill retained in the pocket.

f the bill has properly made the switches 114 and 136 and the latchingmeans has been operated, the motor driven rotor then takes over forcontrolling the subsequent operations of the device. Assuming, for themoment, as in the previous systems described in the aforementionedcopending applications, that the switch relay 192 is operative to makethe switch 194 thereby to short-circuit the potentiometer 196 and itsassociated resistance coil 198 and switch 290, as the rotor is turned tobring the arm into engagement with the light strip 182, current willflow through line 2st to the lamps 32 to cause their illumination. Ifthe areas of the dollar bill overlying the cells 34* and 34 areeffective to prevent light transmission in an amount sufficient toactivate the relay 204 the switches 2% and 2% remain closed. If theareas of the dollar bill overlying the cells 34 permit transmission oflight in the amount to activate the relay 210, the switches 212 and 214will be made. Then, upon contact of the rotor with the stripper strip186, current will be able to flow through the lines 216, through theswitch 2% and through the switch 214 to the stripper motor 102 to effectturning movement of the shafts 92 and 94 on which the rollers 96 and 98are mounted.

Responsive to operation of the stripper motor 102, the stripper switch218 is made, as by displacement of the drive shaft itlil, for passage ofcurrent to the stripper solenoid '74. This effects retraction of the rod76 with concurrent displacement of the stripper plate '72 to itsoperated position. As the stripper is displaced from its retractedposition to operated position through the aligned slots s2, 64 and 65,it engages the central portion of the dollar bill 26 whereby the bill isfolded and carried with the stripper through the slot as and into thenip of the underlying pair of rollers as and 98. As the edges of thedollar bill are brought into engagement with the rollers, the rollerstake over from the stripper to continue displacement of the folded billfor delivery into a suitable receiver. As the folded bill is carried bythe rollers beyond the stripper, the leading edge engages the switch arm110 to effect displacement thereof whereby the switch 112 is made.

It will be apparent that the black cells and the green cells 34 and 34are each connected in parallel so that if any one becomes energized bythe transmission of light in excess of the amount calculated, then therelay 204 will be operated to open the switches 2% and 2&8. Under suchcircumstances, indicating failure of the paper to meet the test foracceptability, the paper will remain in the slide plate for return withthe slide plate to starting position outside of a housing enclosing thetest section.

Whether or not the paper or dollar bill is acceptable, continuedmovement of the motor driven rotor on the printed circuit 229 will bringthe rotor into contact with the reset strip 133 to enable current toflow through line 272 to the reset relay 224 which operates throughlines connected therewith to reset the solenoid 74 and 158 and thevarious switches thereby to inactivate the 6 lock solenoid and releasethe slide plate for return to normal position. It will be apparent thatupon operation of the reset relay 224, current will be incapable of flowby the usual path to the driving motor 174. In order to continueoperation of the rotor to complete the cycle of the printed circuit, useis made of the motor strip 199 to transmit current directly to thetiming motor 174 through line 226. Thus the motor 174 will continue tooperate until the rotor is returned to starting position.

In order for the change or other dispensing motor 228 to operate,current will have to flow through the switch 112 which is made inresponse to the displacement of the bill from the slide plate. In orderfor current to flow to switch 112, it will be necessary for current toflow through the switch members 114 and 116 and it is capable only offlow therethrough to the switch 112 when the switches are unmade inresponse to the release of the switch arms 11% upon removal of thedollar bill from the slide plate. Thus the dollar bill will have to beremoved from the slide plate and displaced to make the switch 112 forflow of current to the motor 228 and the switches 2%, 2&8, 212 and 214will also have to remain made in the line.

The foregoing is a brief description of the device and its operation asdefined in the foregoing copending applications. The improvementembodying the concepts of this invention resides in the modification ofthe light transmission test whereby the test is made more critical fromthe standpoint of separating paper or currency in accordance with theamount of light capable of transmission through the areas of high lighttransmission. It has been found that duplication may be possible asbetween areas of high light transmission and low light transmission suchthat one would be able to produce a counterfeit that would be capable ofmaintaining the light transmission test. However, such counterfeiting ismade extremely more difficult when acceptance can be made dependent uponthe amount of light transmission through the areas of high lighttransmission thereby to incorporate a light transmission analysis of thepaper or other material upon which the imprints are formed.

For this purpose, modification is made in the wiring diagram andconstruction as illustrated in FIG. 7 of the drawings. Added to theconstruction and assembly is a resistor 198 and potentiometer 1% and anadditional circuit including a slave relay 192 controlled by the contactstrip 184 of the printed circuit and connected at one of the contacts ofswitch 1% to the relay 2% for controlling the contact switches Ziid and203.

' In operation, the potentiometer 1% is set to effect closure of thecontacts of relay W at a predetermined maximum current generated by thewhite cells 34 underlying selected areas of the paper or currency havinglL'gh light transmission. When the rotor of the printed circuit contactsthe light strip 132 and the lights 32 are energized, the currentgenerated by the cells 34' travels. through the circuit including thepotentiometer. If the current is in excess of that for which theresistor and potentiometer are set, then the closed contacts of relay wcauses current to travel from line 23% to line 2% and through thecontact switch 1% into line 242. Line 242 leads to the relay 204- tocause the relay to open the contacts 266 and 298 with the result thatthe device will operate as though excess light had been transmittedthrough one or more of the areas overlying the black or green cells 34*or 34 leading to failure of the paper or currency to meet the test withthe resulting operation as previously described. If the amount of lighttransmitted through to the white cells is incapable of exceeding themaximum for current generation, then the relay 2624 is unaffected and,from the standpoint of the amount of light transmitted through the areascapable of high light transmission, the initial test is indicative ofthe availability of the paper or currency to meet the test.

Now, as the rotor continues about the printed circuit and comes intocontact with the relay strip 184, the current travels through the line244 to the switch relay 192 to break the contact 194 and the switch 20%whereby the resistor and potentiometer are disconnected from the circuitand the white cells are no longer capable of effecting operation of therelay 204. Under such circumstances, the test reverts to the originalcondition, as earlier described, to determine if the amount of lighttransmission through the paper or currency is sufificient. The currentfrom the cells 34 bypasses the resistor and potentiometer. If sufiicientcurrent is generated by the cells to close the contacts of relay w, thecurrent in line 23!) travels through the line 240 through the switch 194into the line 246 leading into the relay 210 whereby the switches 212and 214 are made if the amount of light transmission is suflicient.

The addition of the circuit which includes the potentiometer andresistor comprises the additional test which is operative for the lengthof time that the rotor travels from contact with the light strip 182 tothe relay strip 184 to make use of the white cells 34 for testing to seethat the amount of light transmission is not excessive and which,through switch-over to make use of the same unit, operates to determinewhether sufiicient amount of light is transmitted through the paper orcurrency.

This combination of additional light transmission tests now brings thepaper or material as an element of the test to determine whether asupport having the proper light transmission characteristics has beenused.

It will be apparent that the described test device and means may beemployed for various purposes other than in testing and selectingcurrency or in the operation of a change-making device and it will befurther understood that all or part of these tests may be employedseparately or in combination to effect a desirable test of a materialcapable of some degree of light transmission.

It will be understood that numerous changes may be made in the detailsof construction, arrangement and operation without departing from thespirit of the invention, especially as defined in the following claims.

I claim:

1. A device for testing to determine the acceptability of a sheetmaterial capable of transmission of radiations, portions of which arecapable of high transmission while others are capable only of lowtransmission, including a means for introducing the material to a testposition, a source of radiations on one side of the material when intest position, a plurality of radiation responsive cells on the oppositeside of the material in test position some of which are positioned tounderlie areas of the material calculated to be capable of hightransmission and others of which are in position to underlie areas ofthe material calculated to be capable of low transmission, an electricalcircuit having switch means therein some of which are open and some ofwhich are closed, means controlling the closed switch means through theresponse of the cells underlying areas having low transmission wherebythe closed switch means are opened to interrupt the circuit in the eventof transmission of excessive radiations to said last mentioned cells,means controlling the open switch means through the response of thecells underlying the areas calculated to have high transmission wherebythe open switch means are closed in response to the transmission ofsufiicient radiations through the material to the cells, the improvementwhich comprises means for initially connecting the cells underlying theareas calculated to have high transmission with the closed switch means,means for setting the current from the cells whereby the closed switchmeans are opened in response to the transmission of excessive radiationsthrough the material to the cells, and means for subsequentlyshort-circuiting said latter means for reconnecting the cells with theopen switch means for closing the open switch means in response to thetransmission of sufiicient radiations through the material to the cells.

2. A device for determining the acceptability of sheet material capableof light transmission, portions of which are capable of high lighttransmission while others are capable only of low light transmission andincluding a means for introducing a material to a test position, a lightsource on one side of the material in test position, a plurality oflight responsive cells on the opposite side of the material in testposition, some of which are positioned to underlie areas of the materialcalculated to be capable of high light transmission, others of which arepositioned to undelie areas of the material calculated to be capable oflow light transmission, an electrical circuit embodying switch meanstherein some of which are open and some of which are closed, meansnormally controlling the closed switch means through the response ofcells underlying the areas having low light transmission whereby theclosed switch means are opened to interrupt the circuit in response tothe transmission of excessive light through the material to said lastmentioned cells and means controlling the open switch means through theresponse of the cells underlying the areas calculated to have high lighttransmission whereby the open switch means are closed in response to thetransmission of sutficient light through the material to the cells, theimprovement which comprises means operative initially to connect thecells underlying the areas calculated to have high light transmissionwith the closed switch means, and means for setting the current from thecells whereby the closed switch means are opened in response to thetransmission of excessive light through the material to the cells.

3. A device for testing to determine the acceptability of a sheetmaterial capable of transmission of radiations, portions of which arecapable of high transmission and others of which are capable only of lowtransmission comprising a means for introducing the material to a testposition, a source of radiations on one side of the material when intest position, a plurality of radiation responsive cells on the oppositeside of the material in test position some of which are positioned tounderlie areas of the material calculated to be capable of hightransmission and others of which are in position to underlie areas ofthe material calculated to be capable of low transmission, an electricalcircuit having switch means therein some of which are open and some ofwhich are closed, means controlling the closed switch means through theresponse of the cells underlying areas having low transmission wherebythe closed switch means are opened to interrupt the circuit in the eventof transmission of excessive radiations to said last-mentioned cells,means controlling the open switch means through the response of thecells underlying the areas calculated to have high transmission wherebythe open switch means are closed in response to the transmission ofsufiicient radiations through the material to the cells, means forinitially conmeeting the cells underlying the areas calculated to havehigh transmission with the closed switch means, means for setting thecurrent from the cells whereby the closed switch means are opened inresponse to the transmission of excessive radiations through thematerial to the cells, and means for subsequently short-circuiting saidlatter means for reconnecting the cells with the open switch means forclosing the open switch means in response to the transmission ofsufficient radiations through the material to the cells.

4. A device for determining the acceptability of sheet material of lighttransmission, portions of which are ca pable of high light transmissionwhile others are capable only of low light transmission, comprising ameans for introducing a material to a test position, a light source onone side of the material in test position, a plurality of lightresponsive cells on the opposite side of the material in test position,some of which are positioned to underlie areas of the materialcalculated to be capable of high light transmission, others of which arepositioned to underlie areas of the material calculated to be capable oflow light transmission, an electrical circuit embodying switch meanstherein some of which are open and some of which are closed, meansnormally controlling the closed switch means through the response ofcells underlying the areas having low light transmission whereby theclosed switch means are opened to interrupt the circuit in response tothe transmission of excessive light through the material to said lastmentioned cells and means controlling the open switch means through theresponse of the cells underlying the areas calculated to have high lighttransmission whereby the open switch means are closed in response to thetransmission of suflicient light through 10 the materials to the cells,means operative initially to connect the cells underlying the areascalculated to have high light transmission with the closed switch means,and means for setting the current from the cells whereby the closedswitch means are opened in response to the transmission of excessivelight through the material to the cells.

References Cited in the file of this patent UNITED STATES PATENTS EttJan. 26, 1960 2,941,187 Simjian June 14, 1960

1. A DEVICE FOR TESTING TO DETERMINE THE ACCEPTABILITY OF A SHEETMATERIAL CAPABLE OF TRANSMISSION OF RADIATIONS, PORTIONS OF WHICH ARECAPABLE OF HIGH TRANSMISSION WHILE OTHERS ARE CAPABLE ONLY OF LOWTRANSMISSION, INCLUDING A MEANS FOR INTRODUCING THE MATERIAL TO A TESTPOSITION, A SOURCE OF RADIATIONS ON ONE SIDE OF THE MATERIAL WHEN INTEST POSITION, A PLURALITY OF RADIATION RESPONSIVE CELLS ON THE OPPOSITESIDE OF THE MATERIAL IN TEST POSITION SOME OF WHICH ARE POSITIONED TOUNDERLIE AREAS OF THE MATERIAL CALCULATED TO BE CAPABLE OF HIGHTRANSMISSION AND OTHERS OF WHICH ARE IN POSITION TO UNDERLIE AREAS OFTHE MATERIAL CALCULATED TO BE CAPABLE OF LOW TRANSMISSION, AN ELECTRICALCIRCUIT HAVING SWITCH MEANS THEREIN SOME OF WHICH ARE OPEN AND SOME OFWHICH ARE CLOSED, MEANS CONTROLLING THE CLOSED SWITCH MEANS THROUGH THERESPONSE OF THE CELLS UNDERLYING AREAS HAVING LOW TRANSMISSION WHEREBYTHE CLOSED SWITCH MEANS ARE OPENED TO INTERRUPT THE CIRCUIT IN THE EVENTOF TRANSMISSION OF EXCESSIVE RADIATIONS TO SAID LAST MENTIONED CELLS,MEANS CONTROLLING THE OPEN SWITCH MEANS THROUGH THE RESPONSE OF THECELLS UNDERLYING THE AREAS CALCULATED TO HAVE HIGH TRANSMISSION WHEREBYTHE OPEN SWITCH MEANS ARE CLOSED IN RESPONSE TO THE TRANSMISSION OFSUFFICIENT RADIATIONS THROUGH THE MATERIAL TO THE CELLS, THE IMPROVEMENTWHICH COMPRISES MEANS FOR INITIALLY CONNECTING THE CELLS UNDERLYING THEAREAS CALCULATED TO HAVE HIGH TRANSMISSION WITH THE CLOSED SWITCH MEANS,MEANS FOR SETTING THE CURRENT FROM THE CELLS WHEREBY THE CLOSED SWITCHMEANS ARE OPENED IN RESPONSE TO THE TRANSMISSION OF EXCESSIVE RADIATIONSTHROUGH THE MATERIAL TO THE CELLS, AND MEANS FOR SUBSEQUENTLYSHORT-CIRCUITING SAID LATTER MEANS FOR RECONNECTING THE CELLS WITH THEOPEN SWITCH MEANS FOR CLOSING THE OPEN SWITCH MEANS IN RESPONSE TO THETRANSMISSION OF SUFFICIENT RADIATIONS THROUGH THE MATERIAL TO THE CELLS.